JP5491989B2 - Hydraulic shock absorber - Google Patents

Description

  The present invention relates to a hydraulic shock absorber.

  As a hydraulic shock absorber used in a motorcycle or the like, as disclosed in Patent Document 1, an axle side tube is slidably inserted into a vehicle body side tube, and a damper cylinder is connected to the vehicle body side tube inside the vehicle body side tube. A main piston provided on a piston rod connected to the axle side tube is slidably inserted inside the axle side tube, and the inside of the damper cylinder is partitioned into a piston side oil chamber and a rod side oil chamber by the main piston. The expansion side damping valve is provided in the flow path connecting the piston side oil chamber and the rod side oil chamber of the main piston, and the sub piston facing the main piston is provided above the main piston inside the damper cylinder. The sub tank chamber is partitioned above the piston side oil chamber inside the damper cylinder by the piston side oil chamber of the sub piston. A pressure-side damping valve is provided in the flow path that allows communication with the sub-tank chamber, and a free piston for volume compensation opposite to the sub-piston is movably provided above the sub-piston inside the damper cylinder. Some tubes have a suspension spring interposed between an upper spring support on the vehicle body side tube side and a lower spring support on the axle side tube side.

  In this hydraulic shock absorber, the impact force that the vehicle receives from the road surface is absorbed by the elastic force of the suspension spring and air spring inside the vehicle body side tube. At the same time, the damping force generated by the damping valve device provided on the main piston suppresses expansion and contraction vibration of the vehicle body side tube and the axle side tube accompanying absorption of the impact force by the suspension spring.

Patent 3441479

  In the hydraulic shock absorber described in Patent Document 1, it is desired to adjust the spring load of the suspension spring according to the road surface in order to improve the riding comfort of the vehicle.

  However, in the hydraulic shock absorber described in Patent Document 1, it is difficult to install a spring load adjusting device on both the vehicle body side tube and the axle side tube.

  That is, even if the spring load adjusting device described in, for example, Japanese Patent Application Laid-Open No. 2008-8341 is provided at the lower part of the axle side tube, the presence of the piston rod erected inside the axle side tube prevents the installation of the spring load adjusting device. Make it difficult.

  Further, when the spring load adjusting device described in, for example, Japanese Utility Model Laid-Open No. 2-09037 is provided at the lower part of the axle side tube, the spring load adjusting device greatly protrudes laterally from the outer periphery of the axle side tube, and is damaged when the vehicle falls. There is a fear.

  Also, a damper cylinder is built in the upper part of the vehicle body side tube, and the presence of this damper cylinder makes it difficult to install the spring load adjusting device.

  An object of the present invention is to install a spring load adjusting device in a hydraulic shock absorber in which a damper cylinder is built in an upper portion of a vehicle body side tube.

According to the first aspect of the present invention, an axle side tube is slidably inserted into a vehicle body side tube, and a damper cylinder connected to the vehicle body side tube inside the vehicle body side tube is connected to the axle side tube inside the axle side tube. The main piston provided on the piston rod connected to is slidably inserted, and the main piston divides the inside of the damper cylinder into a piston-side oil chamber and a rod-side oil chamber, and is located above the main piston inside the damper cylinder. A free piston for volume compensation is movably provided, and a suspension spring is provided between the upper spring support on the vehicle body side tube and the lower spring support on the axle side tube inside the vehicle body side tube and the axle side tube. In the hydraulic shock absorber provided with a spring load adjusting device provided on the upper part of the vehicle body side tube, the spring load adjusting device is provided on the vehicle body side tube. The adjust member facing the outside, by lifting the upper spring bearing to adjust the spring load of the suspension spring via an intermediate spring support member provided on the periphery of the damper cylinder in the interior of the vehicle body side tube, said spring load adjusting apparatus, Each has an annular adjusting member screwed around the central axis of the upper end portion of the damper cylinder, and is formed along the axial direction of the damper cylinder at a plurality of circumferential positions of the thick portion on the upper end side of the damper cylinder. A plunger pin is movably inserted into each of the support holes, the upper end surface of the plunger pin is abutted against the lower end surface of the adjustment member, and the upper end surface of the intermediate spring support member is abutted against the lower end surface of the plunger pin. The seal member provided on the outer periphery of the damper is slidably fitted into the support hole of the damper cylinder .

According to a second aspect of the present invention, an axle side tube is slidably inserted into a vehicle body side tube, and a damper cylinder connected to the vehicle body side tube inside the vehicle body side tube is connected to the axle side tube inside the axle side tube. The main piston provided on the piston rod connected to the cylinder is slidably inserted. The main piston partitions the inside of the damper cylinder into a piston-side oil chamber and a rod-side oil chamber. An extension-side damping valve is provided in the flow path connecting the oil chambers, and a sub-piston facing the main piston is provided above the main piston inside the damper cylinder, and this sub-piston supports the piston-side oil chamber inside the damper cylinder. The sub-tank chamber is partitioned upward, and the pressure side damping is applied to the flow path that allows the piston-side oil chamber of the sub-piston and the sub-tank chamber to communicate with each other. A volume compensation free piston facing the sub-piston is movably provided above the sub-piston inside the damper cylinder, inside the body-side tube and the axle-side tube, on the side of the body-side tube. In the hydraulic shock absorber in which a suspension spring is interposed between the upper spring receiver and the lower spring receiver on the axle side tube side, a spring load adjusting device is provided on the upper part of the vehicle body side tube. adjusting device, by adjust member facing the outside of the vehicle body side tube, by lifting the upper spring bearing to adjust the spring load of the suspension spring via an intermediate spring support member provided on the periphery of the damper cylinder in the interior of the vehicle body side tube The spring load adjusting device has an annular adjusting member screwed around the central axis of the upper end portion of the damper cylinder, and the upper portion of the damper cylinder. A plunger pin is movably inserted into each of the support holes drilled along the axial direction of the damper cylinder at a plurality of positions in the circumferential direction of the side thick portion, and the upper end surface of the plunger pin is used as the lower end surface of the adjustment member. The upper end surface of the intermediate spring support member is abutted against the lower end surface of the plunger pin, and the seal member provided on the outer periphery of the plunger pin is slidably fitted into the support hole of the damper cylinder . Is.

The invention according to claim 3 is the invention according to claim 1 or 2, wherein the upper end surface of the plunger pin is inserted into a pin engaging recess provided in the lower end surface of the adjusting member. The adjustment member can be brought into contact with the lower end surface of the adjustment member .

The invention according to claim 4 is the invention according to any one of claims 1 to 3 , wherein the intermediate spring support member comprises a spring collar provided around the damper cylinder, and the spring collar is connected to the outer periphery of the damper cylinder. Are arranged around the damper cylinder so as to form an inner and outer annular space between each of them and the inner circumference of the vehicle body side tube or the axle side tube, and the inner and outer annular spaces are communicated with each other at their upper parts. It is made to have the oil hole which does .

The invention according to claim 5 is the invention according to claim 4 , wherein the guide ring provided at the lower end of the spring collar is in sliding contact with the inner periphery of the axle side tube and is separated from the outer periphery of the damper cylinder. It is.

According to a sixth aspect of the present invention, in the fifth aspect of the present invention, the guide ring further restricts inflow of oil from an oil reservoir near the bottom of the axle-side tube into the outer annular space of the spring collar. A check valve that allows oil to flow out of the annular space into the oil reservoir is provided .

(Claims 1 and 2)
(a) The spring load adjustment device is provided with a spring load adjustment device at the upper part of the vehicle body side tube, and the spring load adjustment device has a damper inside the vehicle body side tube by an adjustment member facing the outside of the vehicle body side tube. The spring load of the suspension spring is adjusted by raising and lowering the upper spring support through an intermediate spring support member provided around the cylinder. Therefore, in the hydraulic shock absorber in which the damper cylinder is built in the upper part of the vehicle body side tube, the spring load adjusting device can be installed on the upper part of the vehicle body side tube by using the annular gap between the vehicle body side tube and the damper cylinder. As a result, the user can easily recognize the presence of the spring load adjusting device, and the operability of the spring load adjusting device is improved.

(b) The spring load adjusting device has an annular adjusting member screwed around the central axis of the upper end portion of the damper cylinder, and the damper cylinder has a plurality of circumferential positions of the thicker portion on the upper end side of the damper cylinder. A plunger pin is movably inserted into each of the support holes drilled along the axial direction, the upper end surface of the plunger pin is abutted against the lower end surface of the adjustment member, and the upper end surface of the intermediate spring support member is placed on the lower end surface of the plunger pin. It was made by hitting the end face. Accordingly, by rotating and rotating the annular adjusting member, the plunger pin is moved along the axial direction of the damper cylinder, and as a result, the upper spring support is moved up and down via the intermediate spring supporting member. The spring load adjustment device can be installed compactly in a narrow space above the vehicle body side tube.

(c) The spring load adjusting device slidably fits the seal member provided on the outer periphery of the plunger pin into the support hole of the damper cylinder. The seal member to be sealed with respect to the air spring chamber inside the vehicle body side tube can be reduced in size, and the seal area can be reduced to a small area. The rotational screwing operability of the adjusting member can be reduced.

(Claim 3 )
(d) When the upper end surface of the plunger pin is immersed in the pin engaging recess provided on the lower end surface of the adjusting member, the adjusting member is rotated and the upper end surface of each plunger pin is immersed in each pin engaging recess. In addition, it can be recognized with a sense of moderation that the adjusting member has rotated by a certain angle (an arrangement interval between adjacent pin engaging recesses), that is, the plunger pin has moved up and down by a certain amount, and the spring load has been adjusted by a certain amount. Further, free rotation of the adjusting member is prevented by the above-described immersion of the plunger pin.

(Claim 4 )
(e) The intermediate spring support member of the spring load adjusting device is formed of a spring collar provided around the damper cylinder, and the spring collar is between the outer periphery of the damper cylinder and the inner periphery of the vehicle body side tube or the axle side tube. The inner and outer annular spaces are arranged around the damper cylinder so as to form inner and outer annular spaces in the middle, and the inner and outer annular spaces have oil holes communicating with each other at the upper part thereof. Therefore, when the vehicle body side tube and the axle side tube expand and contract and the oil level of the oil sump chamber inside the axle side tube rises and falls, the oil in the sump chamber is smoothly transferred from the lower end side of the spring collar to the inner and outer annular spaces. The outer damping force without rigidity due to the pipe resistance of those annular spaces (the damping force generated by the piston valve device and the base valve device inside the damper is called the inner damping force, The generated damping force is referred to as an outer damping force).

  (f) The oil in the oil reservoir chamber flows into the inner annular space (or outer annular space) and generates an outer damping force, and then flows out to the outer annular space (or inner annular space) through the oil hole of the spring collar. The timing and flow path resistance can be adjusted by the position and hole size of each oil hole provided along the axial direction of the spring collar. Thereby, the position dependence regarding the expansion-contraction stroke of a vehicle body side tube and an axle side tube can be provided to the outer side damping force of the above-mentioned (e).

(Claim 5 )
(g) A guide ring provided at the lower end of the spring collar is in sliding contact with the inner periphery of the axle side tube and is separated from the outer periphery of the damper cylinder. In the above (e), the oil in the oil reservoir can smoothly enter and exit from the lower end side of the spring collar directly into the inner annular space, and an outer damping force with less hardness can be obtained.

  (h) The bending load of the lateral force acting on the vehicle body side tube and the axle side tube is not supported by the damper cylinder, and as a result of being supported only by the vehicle body side tube and the axle side tube, it does not become excessively rigid.

(Claim 6 )
(i) The guide ring restricts the inflow of oil from the oil reservoir chamber near the bottom of the axle tube to the outer annular space of the spring collar, and allows oil to flow out of the outer annular space into the oil reservoir chamber. A check valve was provided. In the pressure side stroke, the check valve restricts the inflow of oil from the oil reservoir chamber to the outer annular space, so that the oil in the oil reservoir chamber is guided to the inner annular space to generate a compression side damping force. In the extension stroke, the check valve allows oil to flow out of the outer annular space into the oil reservoir, so that the oil in the outer annular space is smoothly returned to the oil reservoir and the damping force is generated when the pressure is reversed. Avoid (crush).

FIG. 1 is an overall cross-sectional view showing a front fork. 2 is an enlarged cross-sectional view of the lower part of FIG. FIG. 3 is an enlarged cross-sectional view of the middle part of FIG. FIG. 4 is an enlarged cross-sectional view of the upper part of FIG. FIG. 5 is a plan view of FIG. FIG. 6 is a sectional view showing the spring load adjusting device. FIG. 7 is an overall cross-sectional view showing the cylinder tube. FIG. 8 is a top sectional view showing the cylinder tube. FIG. 9 is a plan view of FIG. FIG. 10 shows a fork bolt, (A) is a plan view, and (B) is a sectional view. 11A and 11B show an adjustment member, where FIG. 11A is a top view, FIG. 11B is a cross-sectional view, FIG. 11C is a bottom view, and FIG. FIG. 12 is a front view showing the plunger pin. FIG. 13 is a sectional view showing a reference example of the spring load adjusting device.

As shown in FIGS. 1 to 5, the front fork 10 (hydraulic shock absorber) has an axle side tube (inner tube) 12 slidably inserted into a vehicle body side tube (outer tube) 11, and both tubes 11, 12 are inserted. A suspension spring 13 is interposed therebetween, and the single cylinder damper 14 is inverted and is internally provided.
The vehicle body side tube 11 is supported on the vehicle body side, and the axle side tube 12 is coupled to the axle.

  The upper end portion of the damper cylinder 16 (large diameter upper cylinder tube 16A) (FIGS. 7 to 9) of the damper 14 is screwed to the upper end portion of the vehicle body side tube 11 via an O-ring. The end is closed by a fork bolt 15. The fork bolt 15 is inserted and screwed into the inner periphery of the upper cylinder tube 16A via an O-ring. The fork bolt 15 and the damper cylinder 16 are screwed together so that the outer circumferential step portion of the fork bolt 15 and the inner circumferential step portion of the damper cylinder 16 are abutted and locked in the axial direction, and are integrally coupled.

  An oil lock collar 17 is liquid-tightly fitted to the inner periphery of the lower end portion of the axle side tube 12 via an O-ring, and the oil lock collar is attached to the inner bottom surface of the axle bracket 19 screwed to the outer periphery of the lower end portion of the axle side tube 12. 17 is placed via an O-ring, and the oil lock collar 17 is sandwiched and fixed between the axle side tube 12 and the axle bracket 19. A bottom bolt 18 is externally inserted into the bottom of the axle bracket 19 via an O-ring and is locked and fixed in the axial direction. A base end portion of a piston rod (hollow rod) 20 of the damper 14 is screwed to the bottom bolt 18 and is locked by a lock nut 18 </ b> A, and a tip end portion of the piston rod 20 is inserted into the damper cylinder 16. The piston rod 20 is supported by a bush 21A of a rod guide 21 screwed into an opening on the lower end side of the damper cylinder 16 (small-diameter lower cylinder tube 16B), and is inserted into the damper cylinder 16 through the seal member 21B. Has been. The seal member 21 </ b> B has a unidirectional sealing function that seals an oil chamber 43 </ b> B (described later) of the damper cylinder 16 and prevents the oil in the oil chamber 43 </ b> B from escaping out of the damper cylinder 16. An oil lock piece 22 is provided on the outer periphery of the rod guide 21. A rebound spring 23 is supported on the inner end face of the rod guide 21.

  Inside the vehicle body side tube 11 and the axle side tube 12, a suspension spring 13 is interposed between the upper spring receiver 24 on the vehicle body side tube 11 side and the lower spring receiver 25 on the axle side tube 12 side. Yes. The upper spring receiver 24 is supported by a spring load adjusting device 70 which will be described later, and the lower spring receiver 25 is loaded on the upper surface of the base end portion of the oil lock collar 17.

  An oil reservoir chamber 31 and an air spring chamber 32 are provided inside the vehicle body side tube 11 and the axle side tube 12 and outside the damper 14, and the oil reservoir chamber 31 and the air spring chamber 32 are in contact via a free interface. The air trapped in the air spring chamber 32 constitutes an air spring. The resilient force of the suspension spring 13 and the air spring absorbs the impact force that the vehicle receives from the road surface.

  The damper 14 includes a piston valve device (extension side damping valve device) 40 and a base valve device (pressure side damping valve device) 50. The damper 14 suppresses expansion and contraction vibration of the vehicle body side tube 11 and the axle side tube 12 due to absorption of impact force by the suspension spring 13 and the air spring by the damping force generated by the piston valve device 40 and the base valve device 50.

(Piston valve device 40)
The piston valve device 40 has a piston holder 41 attached to the tip of the piston rod 20, and a main piston 42 attached to the piston holder 41. That is, the main piston 42 provided on the piston rod 20 connected to the axle side tube 12 inside the axle side tube 12 is connected to the damper cylinder 16 of the damper 14 connected to the body side tube 11 inside the body side tube 11. It is slidably inserted. The main piston 42 divides the inside of the damper cylinder 16 into a piston side oil chamber 43A in which the piston rod 20 is not accommodated and a rod side oil chamber 43B in which the piston rod 20 is accommodated, and the damper cylinder 16 (lower cylinder tube 16B). Slide inside. The main piston 42 is provided with an extension side valve 44A and is provided with an extension side flow path 44 that enables communication between the piston side oil chamber 43A and the rod side oil chamber 43B, and a pressure side valve (check valve) 45A. 43 A of pressure side channels 45 which enable communication between 43A and rod side oil chamber 43B are provided.

  Further, the piston valve device 40 passes the damping force adjusting rod 47 coupled to the adjuster 46 through the hollow portion of the piston rod 20, and the needle at the tip of the damping force adjusting rod 47 that advances and retreats in the axial direction by the rotating operation of the adjuster 46. 47A makes it possible to adjust the flow passage area of the bypass passage 48 between the piston-side oil chamber 43A and the rod-side oil chamber 43B provided in the piston holder 41. The adjuster 46 is embedded and held on the lower end face facing the outside of the bottom bolt 18.

(Base valve device 50)
In the base valve device 50, a guide pipe 51 (support shaft) is screwed to the fork bolt 15 screwed to the upper end portion of the upper cylinder tube 16A, and locked by the lock nut 15A. A housing holder 51A is screwed to the tip of the guide pipe 51, and a sub piston 52 is held on the housing holder 51A by a nut 51B or the like. A small-diameter portion 51 </ b> C (communication path) is formed on the upper outer periphery of the guide pipe 51. The sub-piston 52 is disposed above the main piston 42 in the damper cylinder 16 and relatively to the main piston 42, is in liquid-tight contact with the inner peripheral portion of the upper cylinder tube 16A, and is disposed above the piston-side oil chamber 43A. 53 is defined. The sub-piston 52 includes a pressure-side valve 54A so that the piston-side oil chamber 43A and the sub-tank chamber 53 can communicate with each other, and a sub-piston 52 includes an expansion-side valve 55A that connects the piston-side oil chamber 43A and the sub-tank chamber 53. And an extension-side flow channel 55 that enables communication. The housing holder 51 </ b> A includes a bypass path 56 that bypasses the pressure-side flow path 54 and the expansion-side flow path 55 to enable communication between the piston-side oil chamber 43 </ b> A and the sub tank chamber 53.

  The damping force adjustment rod 58 screwed into the fork bolt 15 includes an adjuster 59 and is inserted into the guide pipe 51 and is flown through the bypass flow path 56 by a needle 58A at the tip which is advanced and retracted in the axial direction by the rotation operation of the adjuster 59. The road area can be adjusted. The fork bolt 15 has an adjuster 59 embedded and held at the center of the head end face facing the outside.

  Further, the base valve device 50 is a free piston for volume compensation in the annular space between the upper cylinder tube 16A and the guide pipe 51 inside the upper cylinder tube 16A and above the main piston 42 and the sub piston 52. 61 is movably provided. The free piston 61 is opposed to the sub piston 52. The outer annular groove 61A of the free piston 61 is loaded with an O-ring 62 sandwiched between upper and lower backup rings, and the free piston 61 slides liquid-tightly on the inner periphery of the upper cylinder tube 16A via the O-ring 62. An oil seal 63 is loaded in the inner peripheral recess 61 </ b> B of the free piston 61, and the free piston 61 slides liquid-tightly on the outer periphery of the guide pipe 51 via the oil seal 63. The free piston 61 partitions an oil chamber 53A communicating with the piston-side oil chamber 43A on the sub-piston 52 side of the sub-tank chamber 53 and a volume compensation chamber 53B on the fork bolt 15 side. The volume compensation chamber 53B communicates with the air spring chamber 32 through a communication hole 64 provided on the upper end side of the upper cylinder tube 16A. The fork bolt 15 is provided with an exhaust plug (not shown) for discharging air that has entered the air spring chamber 32 and the volume compensation chamber 53B from the sliding portion of the vehicle body side tube 11 and the axle side tube 12 by the expansion and contraction of the front fork 10. Removably screwed to the side of the head end face. The spring 66 is interposed between the free piston 61 and the fork bolt 15 so as to have a slight initial load at the maximum extension.

  When the piston rod 20 enters the damper cylinder 16 and is compressed, the spring 66 contracts, and the oil chamber in the damper cylinder 16 is pressurized by the amount of the spring load of the spring 66 at this time. Occurrence of cavitation in the oil chamber is prevented, and a delay in the generation of damping force at the time of compression following expansion is avoided.

  The base valve device 50 causes the oil in the oil reservoir chamber 31 adhering to the outer peripheral surface of the piston rod 20 to flow from the seal member 21B of the rod guide portion 21 to the damper cylinder 16 each time the piston rod 20 of the front fork 10 strokes. Bring it inside. As a result, the hydraulic oil in the oil chambers 43A, 43B, 53A inside the damper cylinder 16 gradually increases, the free piston 61 moves upward due to the increase, and the hydraulic oil reaches a certain amount or more. When the inner peripheral seal member 63C reaches the outer peripheral small diameter part 51C (communication path) of the guide pipe 51, excess oil in the damper cylinder 16 is transferred from the oil chamber 53A to the small diameter part 51C, the volume compensation chamber 53B, the communication hole 64, It has a blow function for discharging to the oil reservoir chamber 31 outside the damper cylinder 16 via the air spring chamber 32.

Accordingly, the front fork 10 performs a damping action as follows.
(When compressed)
When the front fork 10 is compressed, a compression side damping force is generated in the base valve device 50 by the oil flowing through the needle 58A of the sub piston 52 or the pressure side valve 54A, and in the piston valve device 40, the oil flowing through the pressure side valve 45A of the main piston 42 is generated. The compression side damping force is set as required.

(When stretched)
When the front fork 10 is extended, in the piston valve device 40, the extension side damping force is generated by the oil flowing through the needle 47A or the extension side valve 44A of the main piston 42, and the base valve device 50 generates almost no damping force.

The damping force on the compression side and the extension side suppresses the stretching vibration of the front fork 10.
When the front fork 10 is most compressed, the oil lock piece 22 at the lower end of the lower cylinder tube 16B of the damper cylinder 16 is fitted to the oil lock collar 17 provided at the lower end of the wheel side tube 12, The oil compressed between them causes an oil lock action and prevents the damper 14 from bottoming.

  Further, when the front fork 10 is fully extended, the lower end surface of the piston holder 41 provided on the piston rod 20 abuts on the rebound spring 23 supported by the rod guide 21 provided on the opening of the damper cylinder 16. , Stretching buffering.

  However, in the front fork 10, a spring load adjusting device 70 for the suspension spring 13 is provided at the upper part of the vehicle body side tube 11.

  The spring load adjusting device 70 raises and lowers the upper spring receiver 24 through an intermediate spring support member 80 provided around the damper cylinder 16 inside the vehicle body side tube 11 by an adjustment member 71 facing the outside of the vehicle body side tube 11. To adjust the spring load of the suspension spring 13.

  As shown in FIG. 6, the spring load adjusting device 70 has an annular adjustment member 71 that is screwed around the central axis of the upper end portion of the damper cylinder 16. A fork bolt 15 (FIG. 10) is screwed to the inner periphery of the upper opening end of the damper cylinder 16 (FIGS. 7 to 9) via an O-ring and faces the outside of the fork bolt 15 and the damper cylinder 16. An adjustment member 71 is loaded in the annular gap. The adjusting member 71 (FIG. 11) is configured so that the outer peripheral screw 71B is attached to the outside of the damper cylinder 16 by using a rotary tool that is engaged with tool engaging holes 71A provided at a plurality of positions arranged at equal intervals in the circumferential direction of the upper end surface. It is screwed to the inner peripheral screw facing the direction. Pin engaging recesses 71 </ b> C are provided at a plurality of positions arranged at equal intervals in the circumferential direction of the lower end surface of the adjusting member 71.

  The spring load adjusting device 70 extends along the axial direction of the upper cylinder tube 16A at a plurality of positions (preferably three positions or more) arranged at equal intervals in the circumferential direction of the upper end thick portion of the upper cylinder tube 16A of the damper cylinder 16. Support holes 16C drilled in this manner, and plunger pins 72 (FIG. 12) are movably inserted into the respective support holes 16C. A small-diameter annular groove is provided on the outer periphery of the intermediate portion in the axial direction of each plunger pin 72, and a seal member 73 such as an O-ring is loaded in the annular groove. Each plunger pin 72 closely fits the seal member 73 to the hole surface of the support hole 16C of the upper cylinder tube 16A so as to be slidable, thereby sealing the air spring chamber 32 to the outside. The upper end surface protruding upward from the support hole 16C of the plunger pin 72 forms a hemispherical end surface in this embodiment, is abutted against the lower end surface of the adjusting member 71, and can be immersed in the pin engaging recess 71C. The lower end surface of the plunger pin 72 protruding downward from the support hole 16 </ b> C is abutted against the upper end surface of the collar 81 at the uppermost end of the intermediate spring support member 80.

  The intermediate spring support member 80 is sequentially laminated from the plunger pin 72 side to the upper spring receiver 24 side, and is divided into a plurality of collars 81, 82, 83, 84, 85 that are sequentially abutted in the axial direction. A guide ring 86 is provided below the collar 85 at the lower end. The collars 81 to 83 are slidably contacted with the outer periphery of the upper cylinder tube 16 </ b> A, and are arranged so as to form an outer annular space 80 </ b> A between the vehicle body side tube 11 and the axle side tube 12. The collar 84 is in sliding contact with the outer periphery of the lower cylinder tube 16B, and is disposed so as to form an outer annular space 80A between the vehicle body side tube 11 and the inner periphery of the axle side tube 12. The collar 85 is disposed so as to form an outer annular space 80A and an inner annular space 80B between the vehicle body side tube 11 and the inner periphery of the axle tube 12 and between the outer periphery of the lower cylinder tube 16B. . The guide ring 86 is fitted to the outer periphery of the lower end of the collar 85, approaches or slides on the inner periphery of the axle-side tube 12, and is separated from the outer periphery of the damper cylinder 16 (lower cylinder tube 16B) via the inner annular space 80B. The upper spring receiver 24 is fitted to the lower end portion of the guide ring 86. Here, the vehicle body side tube 11, the axle side tube 12, the damper cylinder 16 (cylinder tubes 16 </ b> A and 16 </ b> B), the intermediate spring support member 80 (collars 81 to 85), and the guide ring 86 have a substantially cylindrical shape, The annular space 80A and the inner annular space 80B each have a cylindrical cross section. The inner annular space 80B communicates directly with the cylindrical oil reservoir chamber 31 having a larger cross section through an annular gap having a large cross section formed between the inner periphery of the upper spring receiver 24 and the outer periphery of the lower cylinder tube 16B. Yes.

  The intermediate spring support member 80 is provided near the upper end of the collar 85 with an oil hole 85 </ b> A that connects the outer annular space 80 </ b> A and the inner annular space 80 </ b> B to each other at the upper part thereof. The oil holes 85A are provided at a plurality of positions in the circumferential direction of the collar 85, and can also be provided at a plurality of positions in the axial direction of the collar 85.

  The intermediate spring support member 80 restricts the inflow of oil from the oil reservoir chamber 31 near the bottom of the axle tube 12 to the outer annular space 80A of the collar 85 to the guide ring 86, and from the outer annular space 80A to the oil reservoir chamber 31. A check valve 87 that allows oil to flow out is provided. The check valve 87 of the present embodiment is an annular body loaded in an annular groove 86A provided on the outer periphery of the guide ring 86, and the axial length of the check valve 87 is shorter than the axial length of the annular groove 86A. The outer periphery of the check valve 87 is in sliding contact with the inner periphery of the axle-side tube 12, and the inner periphery of the check valve 87 forms an annular flow path 86B between the groove bottom outer peripheral surface of the annular groove 86A. The guide ring 86 includes a communication hole 86 </ b> C that communicates the bottom of the annular groove 86 </ b> A to the oil reservoir 31.

  In the pressure side stroke of the front fork 10, the check valve 87 moves upward in the annular groove 86A due to the pressure applied by the oil reservoir chamber 31, hits the upper wall surface of the annular groove 86A, and the annular flow path 86B to the outer annular space 80A. Is closed to restrict the inflow of oil from the oil reservoir 31 to the outer annular space 80A. The oil in the oil reservoir chamber 31 is guided to the inner annular space 80B, and generates a compression side damping force due to the pipe resistance of the inner annular space 80B.

  In the extension side stroke of the front fork 10, the check valve 87 moves downward in the annular groove 86A by the pressure reducing force of the oil reservoir 31, hits the lower wall surface of the annular groove 86A, and the annular flow path 86B from the outer annular space 80A. As a result, the communication hole 86 </ b> C is opened to allow the oil to smoothly flow out from the outer annular space 80 </ b> A to the oil reservoir 31.

The front fork 10 has the following operational effects.
(a) The spring load adjusting device 70 is provided with the spring load adjusting device 70 at the upper part of the vehicle body side tube 11. The spring load adjusting device 70 is adjusted by the adjustment member 71 facing the outside of the vehicle body side tube 11. The upper spring receiver 24 is moved up and down via an intermediate spring support member 80 provided around the damper cylinder 16 inside the side tube 11 to adjust the spring load of the suspension spring 13. Therefore, in the front fork 10 in which the damper cylinder 16 is built in the upper portion of the vehicle body side tube 11, the spring load adjusting device 70 is provided on the upper portion of the vehicle body side tube 11 by using the annular gap between the vehicle body side tube 11 and the damper cylinder 16. Can be installed. As a result, the user can easily recognize the presence of the spring load adjusting device 70 and the operability of the spring load adjusting device 70 is also improved.

  (b) The spring load adjusting device 70 has an annular adjusting member 71 screwed around the central axis of the upper end portion of the damper cylinder 16, and at a plurality of positions in the circumferential direction of the thick portion on the upper end side of the damper cylinder 16. Plunger pins 72 are movably inserted into the respective support holes 16C drilled along the axial direction of the damper cylinder 16, the upper end surface of the plunger pin 72 abuts against the lower end surface of the adjusting member 71, and the plunger pin 72 The upper end surface of the intermediate spring support member 80 is abutted against the lower end surface of the intermediate spring. Therefore, the plunger pin 72 is moved along the axial direction of the damper cylinder 16 by rotating and rotating the annular adjusting member 71, and as a result, the upper spring receiver 24 is moved up and down via the intermediate spring support member 80. The spring load adjusting device 70 can be compactly installed in a narrow space above the vehicle body side tube 11.

  When the upper end surface of the plunger pin 72 is immersed in the pin engaging recess 71C provided on the lower end surface of the adjusting member 71, the adjusting member 71 is rotated and the upper end surface of each plunger pin 72 is moved into each pin engaging recess 71C. It is a feeling of moderation that the adjusting member 71 is rotated by a certain angle (the arrangement interval of the adjacent pin engaging recesses 71C) every time it is immersed, and the plunger pin 72 is moved up and down by a certain amount, and the spring load is adjusted by a certain amount. Can be recognized. Further, free rotation of the adjusting member 71 is prevented by the above-described immersion of the plunger pin 72.

  (c) The spring load adjusting device 70 slidably fits the seal member 73 provided on the outer periphery of the plunger pin 72 into the support hole 16 </ b> C of the damper cylinder 16. The seal member 73 that should seal the installation portion of the spring load adjusting device 70 extending from the outside to the inside of the vehicle body side tube 11 with respect to the air spring chamber 32 inside the vehicle body side tube 11 is reduced in size, and the seal area is reduced to a small area. Therefore, the rotational screwing operability of the adjusting member 71 can be lightened.

  (d) The intermediate spring support member 80 of the spring load adjusting device 70 includes a spring collar 85 provided around the damper cylinder 16, and the spring collar 85 is between the outer periphery of the damper cylinder 16 and the vehicle body side tube 11 or the axle. The inner and outer annular spaces 80A and 80B are disposed around the damper cylinder 16 so as to form the inner and outer annular spaces 80A and 80B, respectively, and the inner and outer annular spaces 80A and 80B communicate with each other at their upper portions. An oil hole 85A is provided. Accordingly, when the vehicle body side tube 11 and the axle side tube 12 expand and contract and the oil level of the oil reservoir chamber 31 inside the axle side tube 12 rises and falls, the oil in the oil reservoir chamber 31 is removed from the lower end side of the spring collar 85. Smoothly entering and exiting the inner and outer annular spaces 80A and 80B, and the outer damping force having no hardness caused by the pipe resistance of the annular spaces 80A and 80B (the piston valve device 40 and the base valve device 50 inside the damper 14 are The generated damping force is referred to as an inner damping force, and the damping force generated outside the damper 14 is referred to as an outer damping force).

  (e) After the oil in the oil reservoir 31 flows into the inner annular space 80B (or the outer annular space 80A) to generate an outer damping force, the outer annular space 80A (or the inner side through the oil hole 85A of the spring collar 85). The timing of flowing out into the annular space 80B) and the flow path resistance can be adjusted by the position and hole size of each oil hole 85A provided along the axial direction of the spring collar 85. Thereby, the position dependence regarding the expansion-contraction stroke of the vehicle body side tube 11 and the axle side tube 12 can be provided to the outer side damping force of the above-mentioned (e).

  (f) A guide ring 86 provided at the lower end of the spring collar 85 is in sliding contact with the inner periphery of the axle tube 12 and is separated from the outer periphery of the damper cylinder 16. In the above (e), the oil in the oil reservoir 31 can smoothly and smoothly enter the inner annular space 80B directly from the lower end side of the spring collar 85, and an outer damping force with less hardness can be obtained.

  (g) The bending load of the lateral force acting on the vehicle body side tube 11 and the axle side tube 12 is not supported by the damper cylinder 16 but is supported only by the vehicle body side tube 11 and the axle side tube 12. Does not become rigid.

  (h) Inflow of oil from the oil reservoir chamber 31 near the bottom of the axle-side tube 12 to the outer annular space 80A of the spring collar 85 is restricted to the guide ring 86, and from the outer annular space 80A to the oil reservoir chamber 31. A check valve 87 that allows oil outflow was provided. In the pressure side stroke, the check valve 87 restricts the inflow of oil from the oil reservoir chamber 31 to the outer annular space 80A. Therefore, the oil in the oil reservoir chamber 31 is guided to the inner annular space 80B to generate a compression side damping force. In the extension side stroke, the check valve 87 allows the oil to flow out from the outer annular space 80A to the oil reservoir chamber 31, so that the oil in the outer annular space 80A is returned smoothly to the oil reservoir chamber 31, and is attenuated when reversing the pressure side. Avoid power generation.

  The front fork 10A shown in FIG. 13 is substantially different from the front fork 10 shown in FIGS. 1 to 12 in that a spring load adjusting device 90 is used instead of the spring load adjusting device 70.

  In the front fork 10 </ b> A of FIG. 13, the upper end of the damper cylinder 16 (upper cylinder tube 16 </ b> A) is not screwed to the upper end of the vehicle body side tube 11, and the inner periphery of the upper end portion of the vehicle body side tube 11. A cap 91 fixed by being screwed through an O-ring was provided, and the upper cylinder tube 16 </ b> A was supported on the inner periphery of the cap 91. That is, the outer periphery on the upper end side of the upper cylinder tube 16A is inserted into the inner periphery on the upper end side of the cap 91 via the seal member 92 made of an O-ring so as to be relatively rotatable. The outer periphery on the upper end side of the upper cylinder tube 16A is closely and rotatably inserted into the inner periphery on the upper end side of the cap 91 via a seal member 92, thereby sealing the air spring chamber 32 to the outside. The guide portion 91A provided on the upper end side of the cap 91 is sandwiched and held by the upper end flange portion of the upper cylinder tube 16A and the lock nut 93 that is screwed to the outer periphery of the upper cylinder tube 16A. As a result, the damper cylinder 16 is rotatably supported by the guide portion 91A of the cap 91 and is substantially immovable in the axial direction in a state of being integrally coupled to the fork bolt 15 as described above.

  The spring load adjusting device 90 is provided with a polygonal tool engaging surface on the outer peripheral portion near the upper end of the fork bolt 15 facing the outside of the vehicle body side tube 11, and this fork bolt 15 is used as the adjusting member 94. While the fork bolt 15 and the damper cylinder 16 are rotated integrally by the adjustment member 94, the upper spring receiver 24 is moved up and down via an intermediate spring support member 95 provided around the damper cylinder 16 inside the vehicle body side tube 11. The spring load of the suspension spring 13 is adjusted.

  The spring load adjusting device 90 has an adjustment nut 96 screwed to the outer periphery of the upper cylinder tube 16A inside the vehicle body side tube 11 with respect to the rotation preventing portion 91B provided on the cap 91 on the vehicle body side tube 11 side. The upper cylinder tube 16 </ b> A is engaged so as to be movable only in the axial direction, and the upper end surface of the intermediate spring support member 95 is brought into contact with the lower end surface of the adjusting nut 96. In the present embodiment, the rotation prevention pins 97 are fitted at a plurality of circumferential positions on the outer periphery of the adjustment nut 96, and the tip end portions of the rotation prevention pins 97 are extended in the axial direction of the inner periphery of the cap 91. Engages with the circular groove-shaped detent 91B. Thereby, the adjustment nut 96 is regulated so as to be movable only in the direction along the axial direction of the upper cylinder tube 16A.

  In the spring load adjusting device 90, the intermediate spring support member 95 that is abutted against the lower end surface of the adjustment nut 96 is laminated in order from the adjustment nut 96 side to the upper spring receiver 24 side, and abutted in the axial direction. .. Are divided into a plurality of washers 95A, covers 95B, 95C... And a guide ring 86 similar to that in the front fork 10 is provided below them. A lower limit stopper 98 for restraining the washer 95A is provided at the lower end of the threaded portion to which the adjustment nut 96 is screwed on the outer periphery of the upper cylinder tube 16A.

The front fork 10A has the following effects.
(a) The spring load adjusting device 90 is provided with the spring load adjusting device 90 on the upper portion of the vehicle body side tube 11, and the spring load adjusting device 90 is adjusted by the adjusting member 94 facing the outside of the vehicle body side tube 11. The upper spring receiver 24 is moved up and down via an intermediate spring support member 95 provided around the damper cylinder 16 inside the side tube 11 to adjust the spring load of the suspension spring 13. Therefore, in the front fork 10A in which the damper cylinder 16 is built in the upper portion of the vehicle body side tube 11, the spring load adjusting device 90 is provided on the upper portion of the vehicle body side tube 11 by using the annular gap between the vehicle body side tube 11 and the damper cylinder 16. Can be installed. Thereby, it is easy for a user to recognize the presence of the spring load adjusting device 90, and the operability of the spring load adjusting device 90 is improved.

  (b) The spring load adjusting device 90 has an adjusting member 94 integrally coupled to the upper end portion of the damper cylinder 16, and an adjustment nut 96 screwed to the outer periphery of the damper cylinder 16 is provided on the vehicle body side tube 11 side. The non-rotating portion 91B is engaged so as to be movable only in the direction along the axial direction of the damper cylinder 16, and the upper end surface of the intermediate spring support member 95 is abutted against the lower end surface of the adjusting nut 96. Accordingly, the adjustment nut 94 is moved along the axial direction of the damper cylinder 16 by rotating and screwing the adjustment member 94, and as a result, the upper spring receiver 24 is moved up and down via the intermediate spring support member 95. The spring load adjusting device 90 can be compactly installed in a narrow space above the vehicle body side tube 11.

  In the front fork 10A, the front fork 10 also has the effects (c) to (h) described above.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration of the present invention is not limited to this embodiment, and even if there is a design change or the like without departing from the gist of the present invention. It is included in the present invention.

The present invention relates to a damper cylinder that is slidably inserted into a vehicle body side tube and is connected to the vehicle body side tube inside the vehicle body side tube, and a piston that is connected to the axle side tube inside the axle side tube. A main piston provided on the rod is slidably inserted, and the inside of the damper cylinder is divided into a piston-side oil chamber and a rod-side oil chamber by this main piston, and volume compensation is made above the main piston inside the damper cylinder. A free piston is movably provided, and a suspension spring is interposed between the upper spring support on the vehicle body side tube and the lower spring support on the axle tube side inside the vehicle body side tube and the axle side tube. In this hydraulic shock absorber, a spring load adjusting device is provided on the upper part of the vehicle body side tube, and the spring load adjusting device faces the outside of the vehicle body side tube. By adjusting member, thereby lifting the upper spring bearing to adjust the spring load of the suspension spring via an intermediate spring support member provided on the periphery of the damper cylinder in the interior of the vehicle body side tube, the spring load adjusting apparatus, the damper cylinder Each of the support holes drilled along the axial direction of the damper cylinder at a plurality of positions in the circumferential direction of the thick portion of the upper end side of the damper cylinder has an annular adjusting member screwed around the central axis of the upper end portion. Each plunger pin is movably inserted, the upper end surface of the plunger pin is abutted against the lower end surface of the adjustment member, the upper end surface of the intermediate spring support member is abutted against the lower end surface of the plunger pin, and the outer periphery of the plunger pin is The provided seal member is slidably fitted into the support hole of the damper cylinder . As a result, the spring load adjusting device can be installed in the hydraulic shock absorber in which the damper cylinder is built in the upper part of the vehicle body side tube.

10 front fork (hydraulic shock absorber)
11 Car body side tube 12 Axle side tube 13 Suspension spring 16 Damper cylinder 16A, 16B Cylinder tube 20 Piston rod 24 Upper spring receiver 25 Lower spring receiver 31 Oil reservoir chamber 32 Air spring chamber 40 Piston valve device 42 Main piston 43A Piston side oil chamber 43B Rod side oil chamber 44 Flow path 44A Stretch side valve (stretch side damping valve)
50 Base valve device (damping valve device)
51 Guide pipe (support shaft)
52 Sub-piston 53 Sub-tank chamber 54 Flow path 54A Pressure side valve (pressure side damping valve)
61 Free piston 70 Spring load adjusting device 71 Adjusting member 72 Plunger pin 73 Sealing member 80 Intermediate spring supporting member 85 Spring collar 85A Oil hole 86 Guide ring 87 Check valve

Claims (6)

Insert the axle side tube slidably into the body side tube,
The main piston provided on the piston rod connected to the axle side tube inside the axle side tube is slidably inserted into the damper cylinder connected to the body side tube inside the body side tube. The inside of the cylinder is divided into a piston side oil chamber and a rod side oil chamber,
Inside the damper cylinder, a free piston for volume compensation is movably provided above the main piston.
In the hydraulic shock absorber in which a suspension spring is interposed between the upper spring receiver on the vehicle body side tube side and the lower spring receiver on the axle side tube side inside the vehicle body side tube and the axle side tube,
A spring load adjustment device is provided at the top of the vehicle body side tube.
The spring load adjustment device uses an adjustment member that faces the outside of the vehicle body side tube to raise and lower the upper spring receiver via an intermediate spring support member provided around the damper cylinder inside the vehicle body side tube, to thereby apply the spring load of the suspension spring. adjusted,
The spring load adjusting device is
Having an annular adjustment member screwed around the central axis of the upper end of the damper cylinder;
A plunger pin is movably inserted into each of the support holes drilled along the axial direction of the damper cylinder at a plurality of positions in the circumferential direction of the thick portion on the upper end side of the damper cylinder, and the upper end surface of the plunger pin is an adjustment member The upper end surface of the intermediate spring support member is abutted against the lower end surface of the plunger pin, and the seal member provided on the outer periphery of the plunger pin is slidably fitted into the support hole of the damper cylinder. hydraulic shock absorber characterized by comprising. Insert the axle side tube slidably into the body side tube,
The main piston provided on the piston rod connected to the axle side tube inside the axle side tube is slidably inserted into the damper cylinder connected to the body side tube inside the body side tube. The inside of the cylinder is divided into a piston-side oil chamber and a rod-side oil chamber, and an expansion-side damping valve is provided in the flow path connecting the piston-side oil chamber and the rod-side oil chamber of the main piston,
A sub-piston facing the main piston is provided above the main piston inside the damper cylinder, and the sub-piston chamber is defined above the piston-side oil chamber inside the damper cylinder by the sub-piston. A pressure-side damping valve is provided in the flow path that enables communication between the sub tank chamber and
Inside the damper cylinder, a free piston for volume compensation opposite to the sub-piston is provided above the sub-piston so as to be movable,
In the hydraulic shock absorber in which a suspension spring is interposed between the upper spring receiver on the vehicle body side tube side and the lower spring receiver on the axle side tube side inside the vehicle body side tube and the axle side tube,
A spring load adjustment device is provided at the top of the vehicle body side tube.
The spring load adjustment device uses an adjustment member that faces the outside of the vehicle body side tube to raise and lower the upper spring receiver via an intermediate spring support member provided around the damper cylinder inside the vehicle body side tube, to thereby apply the spring load of the suspension spring. adjusted,
The spring load adjusting device is
Having an annular adjustment member screwed around the central axis of the upper end of the damper cylinder;
A plunger pin is movably inserted into each of the support holes drilled along the axial direction of the damper cylinder at a plurality of positions in the circumferential direction of the thick portion on the upper end side of the damper cylinder, and the upper end surface of the plunger pin is an adjustment member The upper end surface of the intermediate spring support member is abutted against the lower end surface of the plunger pin, and the seal member provided on the outer periphery of the plunger pin is slidably fitted into the support hole of the damper cylinder. hydraulic shock absorber characterized by comprising. The upper end surface of the plunger pin can be brought into contact with the lower end surface of the adjusting member in a state where the upper end surface of the plunger pin is immersed in a pin engaging recess provided in the lower end surface of the adjusting member . Hydraulic shock absorber. The intermediate spring support member comprises a spring collar provided around the damper cylinder,
The spring collar is disposed around the damper cylinder so as to form an inner and outer annular space between the outer periphery of the damper cylinder and the inner periphery of the vehicle body side tube or the axle side tube. The hydraulic shock absorber according to any one of claims 1 to 3 , further comprising oil holes communicating with each other at an upper portion thereof. The hydraulic shock absorber according to claim 4 , wherein a guide ring provided at a lower end portion of the spring collar is in sliding contact with the inner periphery of the axle-side tube and is separated from the outer periphery of the damper cylinder. A check that restricts the inflow of oil from the oil reservoir near the bottom of the axle tube to the outer annular space of the spring collar and allows the oil to flow out of the outer annular space into the oil reservoir. The hydraulic shock absorber according to claim 5 , wherein a valve is provided.

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